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Transition metal oxides (TMOs) are promising materials for next‐generation lithium‐ion batteries while the lithium storage and cycling stability of TMOs are still limited. Herein, a novel Co3O4/MnO2/C composite using metal‐organic frameworks (MOFs) as sacrificial templates is reported. MnO2 and C shells are layer by layer coated on the MOF‐derived Co3O4/C samples via hydrothermal technique and heat treatment. When employed as anode materials for LIBs, the hierarchically heterostructured Co3O4/MnO2/C composites incorporate the merits of Co3O4, MnO2, and C, showing high Li storage performances at a current density of 0.2 A g−1 with an initial capacity of ∼1245.7 mAh g−1 and a reversible capacity of ∼854.9 mAh g−1 after 100 cycles, remarkable cycling stability, and excellent rate capability (almost 98 % recovery as the current density returns to the initial 0.2 A g−1, and especially, the specific capacity remains ∼587.6 mAh g−1 at a high current density of 2.0 A g−1). [ABSTRACT FROM AUTHOR]

To solve the problem associated with the huge volume change and low conductivity of Mn3O4, a novel C/Mn3O4 microsphere with Mn3O4 layer and void space sandwiched by nitrogen‐doped carbon (NC) is designed and fabricated. In this composite, the NC is obtained from the metal–organic frameworks (MOFs) and polydopamine (PDA). The preparation process is facile and effective without additional templates or redox solvents introduced. When used as anodes for lithium‐ion batteries (LIBs), the C/Mn3O4 composite incorporates the metrics of N‐doping, yolk‐shell structure, double carbon layer, mesoporous Mn3O4, showing an outstanding lithium storage of ≈1015.9 mAh g−1 at 0.2 A g−1 in the 250th cycle, high cycling stability (without clear capacity decay after 400 cycles), and excellent rate capability (capacity can fully recover as the current density returns back to the initial value of 0.2 A g−1). The yolk‐shell structure derived from MOFs can be expanded to fabricate other materials with improved performance. [ABSTRACT FROM AUTHOR]

Silicon nanoparticles (SiNPs) with a median size of 51 nm are prepared by the sand mill from waste silicon, and then carbon-interweaved SiNPs/graphite anode materials are designed. Because of the size of SiNPs is restricted below a critical fracture size of 150 nm as well as the rational decoration of carbon and graphite, fracture of SiNPs, and volume deformation of active materials are highly alleviated, leading to low impedance, enhanced electrochemical reaction kinetics, and good electronic connection between active materials and current collector. Furthermore, delithiation reversibility of the formed crystalline Li 15 Si 4 alloy is enhanced. As a result, the anode with 10.5 wt % content of Si (including SiO x ) delivers a properly high initial reversible capacity of 505 mA h g -1 , high cycling stability with capacity retentions of 86.3%, and 91.5% at 0.1 and 1 A g -1 after 500 cycles, respectively. After cycling at a series of higher current densities, the reversible capacity recovers to the original level completely (100% recovery) when the current density is set back to the original value, exhibiting outstanding rate performance. The results indicate that the silicon-carbon anode can achieve high cycling performances with enhanced delithiation reversibility of the formed crystalline Li 15 Si 4 alloy by restricting size of SiNPs and decoration of carbon materials, which are discussed systematically. The SiNPs are recycled from waste Si, and synthetic strategy of anode materials is very facile, cost-effective, and nontoxic, which has potential for industrial production.